Name:
Math 1040
Midterm Examination
February 19, 2016
Relax and good luck!
Problem
1
2
3
4
5
6
Total
Points
15
15
20
20
20
10
100
Score
1. (3 pts each) Identify the level of measurement for each data set:
(nominal, ordinal, interval or ratio)
(a) The departments of a car dealership:
sales, financing, parts and service, customer service
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(b) The birth years of the students in this class:
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(c) The size-classes of automobiles: subcompact, compact, midsize, large
(d) The heights of the students in this class.
(e) The prices of houses in Salt Lake City.
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2. (3 points each) Describe the method of data collection you would use:
(observational study, experiment, simulation or survey)
(a) To determine whether a sleep aid is effective.
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(b) To estimate the damage of a fifteen foot tsunami hitting Sail Francisco.
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(c) To estimate how many college students intend to vote
(d) To find the prices of a portfolio of 100 stocks.
(e) To determine the favorite foods of Utahns in various age groups.
3. The ages of 10 cars randomly selected from the student parking lot are:
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(a) (10 points) Compute the mean, median and mode of the data:
=Mean=
Median
=
I
Mode=
(b) (10 points) Compute the standard deviation of the data.:
0
=
1/
V
11
-i
.
=
Standard Deviation
=
{i
4. Take the same data as in the previous problem:
4
1264111108512
and put it into 4 classes.
(a) (10 points) Fill out the frequency table for the data:
Classes
i—3
‘1)
7(—k%
Midpoints
Frequencies
3
5-
Cumulative Frequencies
3
3
;.
(b) (10 points) Sketch the frequency histogram for the data with four classes.
5. The heights of a sample of men at a football game was collected and the
data was grouped into five classes with the following frequencies:
Heights
63-65
66-68
69-71
72-74
75-77
Midpt
64
67
70
73
76
Frequencies
3
6
7
4
3
Cc&Y
(a) (10 points) Find the average height of the men.
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Weighted Average
-
=
(b) (10 points) Sketch the ogive for the data.
(Hint: You need to calculate cumulative frequencies for this!)
-
/
5--
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7. An large sample of salaries of elementary school teachers was collected,
from which the following were calculated:
Average salary: $28,000
Standard deviation: $5,000
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Assuming that the distribution of salaries is symmetric and bell-shaped,
use the empirical rule to estimate the percentage of elementary school teach
ers whose salaries fall in the following ranes:
(a) (5 points) Bet
$33,000
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1
-3 dO
-
Percentage
=
Percentage
=
(b) (5 points) More than $38,000